SIGNAL TRANSDUCTION GENE THERAPY (STGT)

Signal transduction refers to the most common method of regulation of complex cell activity. It involves an external signal molecule (ligand) being bound by a specific cell's membrane receptor. The receptor, in turn triggers changes in the internal command system of the cell causing it to undertake a new activity so long as the ligand is present. A powerful new therapy using STGT is being developed whereby part of the genome of a common cold virus is replaced with:
1. A gene or genes that make a therapeutic chemical (e.g. hormone, cytokine etc.) and
2. A gene or genes that regulates the production of the therapeutic genes and that is itself "switched on" by a chemical that can be given to the patient.
In this procedure the patient is infected by the modified virus. The modified viral DNA then remains in the patient's cells. The therapy gene remain inactive until the "triggering" substance was given externally. The amount of triggering substance would determine the degree to which the therapy gene was turned on (like a dimmer switch).